摘要：In an attempt to develop potent antitumor agents,new rhodacyanine analogues containing the pyridinium ring（5a-5h）,the isoquinolinium ring（6a-6c） and the quinolinium ring（7a-7e） linked to the rhodanine ring via N-N covalent bond were designed, synthesized and evaluated for antitumor activity against human lung cancer cell line（H460） by MTT assay in *** of the tested compounds showed enhanced antitumor activity with IC_（50） values ranging from 0.006 to 9.2 u,mol/L as compared to the lead compound *** them,the most promising compound 7d（IC_（50） = 0.006μmol/L） was 216.7 times more active than MKT-077（IC_（50） = 1.3μmol/L）.The preliminary structure-activity relationship of the target compounds was discussed.

摘要：A novel series of 5H-pyridazino[4,5-b]indoles were designed and synthesized in order to find novel potent anticancer compounds. The structures were confirmed by ^1H NMR and MS. Their antiproliferative activities against two cancer cell lines were tested by the MTT method in vitro. Three of compounds （1e, 1g, and 1h） exhibited potent antiproliferative activities, especially compound lh （with IC50 values of 5.2 μmol/L and 1.9 μmol/L against Bel-7402 and HT-1080, respectively）. The preliminary structure-activity relationships of 5H-pyridazino[4,5-b]indole derivatives were discussed.

摘要：In our efforts to identify novel potent anticancer agents, we synthesized a series of 2,7-disubstituted triazolo[1,5-a]pyrimidines （6-16）. Their antiproliferative activity against Bel-7402, HT- 1080 and WI-38 cell lines was tested by MTT assay in vitro. Four of the compounds （9-11 and 16） displayed promising antiproliferative activity superior to gefitinib, especially compound 9. A preliminary SAR study of these derivatives was performed.

摘要：A new series of diaryl urea derivatives bearing N-acylhydrazone moiety were designed and synthesized. All the target compounds were evaluated for their antiproliferative activities against human leukemia cell line （HL-60）, human lung adenocarcinoma epithelial cell line （A549） and human breast cancer cell line （MDA-MB-231） in vitro by standard MTT assay. The pharmacological results indicated that some compounds exhibited promising antitumor activities. Compound 1j showed the most potent antiproliferative activity against the tested three cell lines with IC50 values of 0.13 μmol/L, 0.7 μmol/L and 0.5μmol/L, respectively.

摘要：STEM教育是过几年就冷下去的教改运动吗?不是。但是,作为聚焦国民科技创新素养培养的STEM教育,如果离开了自身的专业化和现代化,将无法生存和成熟。成熟的STEM教育需要具备四个外部特征——问题解决、创中学、设计制造和协作探究,以及两个内部特征——S.T.E.M.知识真实的整合性的应用和科学精神的熏陶与强化。这种STEM教育会是一种全新的教育实践,它需要零起点开发的,数字化、标准化和结构化的,包含教学详案的课程产品,需要“用教学过程说明自身”的教学评价方式,需要专业化的人力资源配置,需要全新的教育产业链。在理论上,STEM教育并不需要旧教育学(Pedagogy),它需要的是新教育学(Educology)。在新教育学的引领下,当下的STEM教育运动是一场教育现代升级转型的机会。

摘要：针对两级式车载充电机的后级全桥LLC谐振变换器,根据锂电池充电策略确定了电压电流双单环竞争的控制方案,并使用PFM+Burst混合控制方法提高LLC谐振变换器的轻载效率。采用等效电路法简化LLC谐振变换器的小信号模型,推导出开关频率到输出电压的传递函数,基于此设计了2p2z型补偿器用于LLC谐振变换器闭环控制。并在全桥LLC谐振变换器实验平台验证了控制方案的正确性。实验表明,该控制方案下变换器工作稳定,恒压恒流输出准确。

摘要：The fuel consumption associated with some interplanetary transfer trajectories using chemical propulsion is not affordable. A solar sail is a method of propulsion that does not consume fuel. Transfer time is one of the most pressing problems of solar sail transfer trajectory design. This paper investigates the time-optimal interplanetary transfer trajectories to a circular orbit of given inclination and radius. The optimal control law is derived from the principle of maximization. An indirect method is used to solve the optimal control problem by selecting values for the initial adjoint vari- ables, which are normalized within a unit sphere. The conditions for the existence of the time-optimal transfer are dependent on the lightness number of the sail and the inclination and radius of the target orbit. A numerical method is used to obtain the boundary values for the time-optimal transfer trajectories. For the cases where no time-optimal transfer trajectories exist, first-order necessary conditions of the optimal control are proposed to obtain feasible solutions. The results show that the transfer time decreases as the minimum distance from the Sun decreases during the transfer duration. For a solar sail with a small lightness number, the transfer time may be evaluated analytically for a three-phase transfer trajectory. The analytical results are compared with previous results and the associated numerical results. The transfer time of the numerical result here is smaller than the transfer time from previous results and is larger than the analytical result.

摘要：In an attempt to develop potent and selective anticancer agents,we designed and synthesized a series of novel bis（morpholino-1,3,5-triazine） derivatives beating aylmethylene hydrazine moiety and evaluated their cytotoxicity,in vitro,against H460（non-small-cell lung cancer）,HT-29（human colorectal cancer） and MDA-MB-231（human breast cancer） cell *** pharmacological results indicate that all the compounds exhibit enhanced cytotoxicity than BMCL-200908069-1,and six target compounds（7e,7h,7j,9a,9b,9c） were superior to PAC-1 against all the tested cancer cell *** most active compound 7j,with IC50（inhibitory concentration 50％）values of 0.75,0.34 and 0.60 μ mol/L against HT-29,H460 and MDA-MB-231 cancer cell lines,was 39-,28-,and 60-fold more potent than BMCL-200908069-1 （29.24,9.52 and 36.21 μmol/L）,respectively.

摘要：针对传统涡轮增压器超高速轴承-转子系统动力学建模精度不高、模态参数不易识别等问题,基于Timoshenko梁理论建立了涡轮增压器动力学模型及运动微分方程,利用锤击法试验对增压器不同激励位置、有无预紧力等工况下的模态参数进行了识别,并将理论与试验分析结果进行了对比验证。研究结果表明:激励涡轮增压器不同位置时,系统的激发模态不尽相同;预紧力对转子动力学分析结果具有重要影响,增加预紧力可显著提高转子刚度;建立的动力学模型和模态识别方法具有一定的准确性和适用性,可以为后续涡轮增压器结构优化设计、模态参数识别提供理论与试验基础。

摘要：针对永磁同步电机(permanent magnet synchronous motor,PMSM)传统模型预测磁链控制(model predictive control,MPFC)系统稳态误差大、参数鲁棒性较差的问题,提出了一种基于定子磁链预测误差矢量分析的永磁同步电机多电压矢量选择方法。首先,在两相静止坐标系下依据轴线划分扇区,制定了判断磁链误差矢量所在区域的多电压矢量选择标准。然后,采用定子磁链预测值和两相静止坐标系定子磁链价值函数计算各电压矢量作用时间,改进了传统模型预测寻优过程。此外,设计了一种考虑电阻、电感参数失配的离散滑模定子磁链观测器,进一步提升了系统的参数鲁棒性。最后,通过仿真和实验验证了本文所提预测定子磁链控制方法的有效性和可行性,系统在参数失配情况下仍具有良好的稳态性能,显著减小了定子磁链与电磁转矩脉动。